Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G77/00—Macromolecular compounds obtained by reactions forming a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon in the main chain of the macromolecule
  • C08G77/04—Polysiloxanes
  • C08G77/06—Preparatory processes
  • C08G77/08—Preparatory processes characterised by the catalysts used
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G77/00—Macromolecular compounds obtained by reactions forming a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon in the main chain of the macromolecule
  • C08G77/04—Polysiloxanes
  • C08G77/06—Preparatory processes
  • C08G77/10—Equilibration processes

Definitions

• the object was now to provide a process for the condensation and / or equilibration of organo (poly) siloxanes in the presence of a catalyst containing phosphorus, nitrogen and chlorine, which does not require the use of solvent to be disposed of, nevertheless a very good distribution of the catalyst in the organo (poly) siloxane to be condensed and / or equilibrated, and is even more effective than the compounds containing phosphorus, nitrogen and chlorine known hitherto as catalysts in the condensation and / or equilibration of organo (poly) siloxanes.
• This object is achieved by the invention.
• the invention relates to a method for condensing and / or equilibrating organo (poly) siloxanes in the presence of a phosphorus, nitrogen and chlorine-containing Catalyst, characterized in that the phosphorus, nitrogen and chlorine-containing catalyst is a reaction product of at least one phosphorus nitride chloride with at least one cyclic diorganopolysiloxane.
• organo (poly) siloxanes any organs (poly) siloxanes with Si-bonded hydroxyl groups can also be used in the process according to the invention, which in the previously known processes for condensing and / or equilibrating organo (poly) siloxanes with Si-bonded hydroxyl groups in In the presence of a phosphorus, nitrogen and chlorine-containing catalyst could be used.
• organo (poly) siloxanes with Si-bonded hydroxyl groups are in particular those of the formula HO (SiR2O) n H, wherein R is the same or different, monovalent, SiC-bonded organic radicals or hydrogen, with the proviso that a monovalent, SiC-bonded organic radical is also bonded to each silicon atom to which hydrogen is bonded, and n is an integer in the Value of at least 1, preferably at least 2.
• n has a value such that the average viscosity of the organo (poly) siloxanes to be condensed and / or equilibrated is at most 1000 mm2.s ⁇ 1 at 25 ° C.
• SiR2O can be present by other siloxane units which are usually only more or less difficult to avoid, such as those of the formula RSiO 3/2 , R3SiO 1 / 2 , where R in each case has the meaning given above, or SiO 4/2 or mixtures of at least two such other siloxane units.
• a type of organo (poly) siloxane with Si-bonded hydroxyl groups can be used in the process according to the invention. Mixtures of at least two different types of such organo (poly) siloxanes can also be used.
• organo (poly) siloxanes with Si-bonded hydroxyl groups or in a mixture with such organo (poly) siloxanes
• cyclic organopolysiloxanes in particular those of the formula, can also be used (R2SiO) m , wherein R has the meaning given above and m is an integer from 3 to 12, in particular 4 to 8, particularly preferably 4, are used in the process according to the invention.
• the SiC-bonded organic radicals in the organo (poly) siloxanes used in the process according to the invention and thus also the organic radicals R in the formulas given above preferably contain at most 18 carbon atoms per radical.
• examples of such radicals are hydrocarbon radicals, such as alkyl radicals, for example the methyl, ethyl, n-propyl, isopropyl, n-butyl and sec-butyl radical and octadecyl radicals; Hydrocarbon radicals with aliphatic multiple bonds, for example the vinyl and allyl radical; Aryl radicals, for example the phenyl radical and xenyl radicals; Alkaryl radicals, for example tolyl radicals; and aralkyl radicals, for example the benzyl radical.
• hydrocarbon radicals can have substituents which are inert to water and the catalyst used according to the invention under the reaction conditions.
• monovalent, SiC-bonded organic radicals in the organo (poly) siloxanes used in the process according to the invention and thus also for organic radicals R in the formulas given above are thus monovalent, halogenated hydrocarbon radicals, such as haloalkyl radicals, for example the 3,3 3-trifluoropropyl radical and haloaryl radicals, for example the o-, p- or m-chlorophenyl radical; monovalent aliphatic radicals composed of carbon, hydrogen, ether oxygen and fluorine atoms, for example the 1,1,2,2,3,3-hexafluoropropyloxypropyl radical and the 1,1,2,2-tetrafluoroethoxypropyl radical, and acyloxyalkyl radicals, such as the gamma-acryloxypropyl group and gamma-methacryloxypropyl group
• At least 80% of the number of organic radicals in the organo (poly) siloxanes used in the process according to the invention and thus also the organic radicals R in the formulas given above are methyl radicals.
• the phosphorus nitride chlorides used for the preparation of the catalysts used according to the invention can be, for example, those obtained by reacting 400 parts by weight of phosphorus pentachloride with 130 parts by weight of ammonium chloride are available (see, for example, "Reports of the German Chemical Society", 57th year, 1924, page 1345), and / or those which can be obtained by reacting 2 moles of phosphorus pentachloride with 1 mole of ammonium chloride (see, for example, US Pat. No. 3,839 388, issued October 1, 1974, S. Nitzsche et al., Wacker-Chemie GmbH). Phosphorus nitride chlorides of the latter type are preferred.
• the cyclic diorganopolysiloxanes which are preferably used for the preparation of the catalysts used according to the invention can be represented by the formula (R1 ⁇ 2 SiO) m are reproduced, wherein R1 is the same or different, monovalent, SiC-bonded organic radicals and m has the meaning given above for it.
• octamethylcyclotetrasiloxane is particularly preferred as the cyclic diorganopolysiloxane to be reacted with at least one phosphorus nitride chloride.
• Cyclic diorganopolysiloxane is preferably used in amounts of 20 to 25 gram atom of silicon atom in this diorganopolysiloxane per gram atom of phosphorus in the phosphoronitride chloride.
• the reaction of phosphorus nitride chloride with cyclic diorganopolysiloxane is preferably carried out by heating a mixture of the two reactants to 120 ° to 180 ° C., in particular 130 ° to 150 ° C., and under pressure from the surrounding atmosphere, i.e. at 1020 hPa (abs.) Or about 1020 hPa (abs.). If desired, higher or lower temperatures and / or higher or lower pressures can also be used.
• reaction products of at least one phosphorus nitride chloride with at least one cyclic diorganopolysiloxane used according to the invention are preferably used in amounts of 0.0001 to 0.1 percent by weight chlorine in these reaction products, based on the total weight of the organo (poly) siloxanes to be polymerized and / or equilibrated.
• Organosilicon compounds which regulate the chain length can also be used in the process according to the invention. Any organosilicon compounds which regulate the chain length can be used, which could also be used in the previously known processes for condensing and / or equilibrating organo (poly) siloxanes in the presence of a catalyst containing phosphorus, nitrogen and chlorine.
• examples for Such chain length regulating organosilicon compounds are especially those of the formula wherein R2 is the same or different monovalent hydrocarbon radicals and z is an integer from 1 to 50.
• Individual examples of such compounds are dimethylpolysiloxane endblocked by trimethylsiloxy groups and having a viscosity at 25 ° C. of 20 mm2.s ⁇ 1, hexamethyldisiloxane and 1,3-divinyl-1,1,3,3-tetramethyldisiloxane.
• the amount of chain length regulating organosilicon compound depends, as is well known to those skilled in the art, on the desired level of molecular weight. The greater the amount of organosilicon compound regulating the chain length, the lower the viscosity and thus the molecular weight of the organopolysiloxanes after the polymerization and / or equilibration.
• the chain length-regulating organosilicon compounds are preferably also used in the process according to the invention.
• the condensation and / or equilibration of the organo (poly) siloxanes is preferably carried out at 100 ° to 200 ° C.
• the condensation and / or equilibration of the organo (poly) siloxanes is preferably carried out at a pressure below 800 hPa (abs.). Condensing, but in particular equilibration, can also be carried out at higher pressures.
• the linear organopolysiloxanes produced according to the invention can be used for all purposes in which it was also possible to use the linear organopolysiloxanes produced by condensing and / or equilibrating organo (poly) siloxanes, for example as thread lubricants, for the preparation of organopolysiloxane elastomers, depending on the type of terminal units of the linear organopolysiloxanes, the crosslinking can take place by condensation, addition of Si-bonded hydrogen to, for example, SiC-bonded vinyl groups or by radical formation, and for the production of coatings which repel tacky substances.
• the phosphorus nitride chloride used in the following examples was prepared as follows:
• a mixture of 417 g (2 mol) of phosphorus pentachloride and 53.5 g (1 mol) of ammonium chloride in 1000 ml of tetrachloroethane is heated to boiling under reflux for 12 hours.
• the constituents boiling under these conditions are distilled off from the pale yellow solution thus obtained at 160 ° C. and by reducing the pressure to about 1.33 hPa (abs.).
• a phosphorus nitride chloride in the form of yellowish crystals is obtained as a residue.
• the organopolysiloxane thus obtained which still has a temperature of almost 150 ° C., is placed in the discharge pipe by means of a gear pump has, with 220 ml per hour of a 1.5 percent by weight solution of triisononylamine in a mixture of cyclic dimethylpolysiloxanes with 3 to 8 silicon atoms per molecule, the proportion of octamethylcyclotetrasiloxane outweighing the proportion of the other cyclic dimethylpolysiloxanes.
• the dimethylpolysiloxane obtained in this way each having an Si-bonded hydroxyl group in the terminal units, has a viscosity of 80,000 mm2.s ⁇ 1 at 25 ° C.
• the organopolysiloxane obtained in this way which still has a temperature of almost 150 ° C., is mixed with 220 ml per hour of a solution consisting of 17 g of n-butyllithium in 9.65 g of n-pentane and 2086.5 g Dimethylpolysiloxane endblocked by trimethylsiloxy groups with a viscosity at 25 ° C. of 350 mm2.s ⁇ 1.
• the dimethylpolysiloxane endblocked by trimethylsiloxy groups thus obtained has a viscosity of 20,000 mPa.s. at 25 ° C.
• Example 1 under b) The procedure described in Example 1 under b) is repeated with the modification that instead of 82 mg of the reaction product of a phosphonitrile chloride with octamethylcyclotetrasiloxane, the preparation of which was described in Example 1 under a), 6.03 mg of phosphonitrile chloride in 0.5 ml of trichloropropane are added will. After 10 minutes, a trimethylsiloxy endblocked dimethylpolysiloxane with a viscosity of 30,000 mm2.s ⁇ 1 at 25 ° C is obtained.

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• 1987
  • 1987-07-31 DE DE19873725377 patent/DE3725377A1/de not_active Withdrawn
• 1988
  • 1988-07-28 EP EP88112197A patent/EP0305737A3/fr not_active Withdrawn
  • 1988-07-29 JP JP18856388A patent/JPS6443528A/ja active Pending

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